Tacrine is the first FDA-approved drug developed in 1993 to treat Alzheimer disease. It is known to inhibit the secretion of acetylcholine produced in brains of Alzheimer disease patients at their early or intermediate stages thereby delaying the process of cognitive impairment. However, it was known to incur adverse effects in connection with liver and is hardly used at present. Aricept, another FDA-approved drug developed in 1996, acts by increasing the usage of acetylcholine and it can prolong its efficacy by a single dosage before bedtime. It has adverse effects such as nausea, diarrhea and fatigue but those symptoms are not so severe and are also easily disappeared. Nevertheless, both tacrine and aricept cannot reverse the onset of Alzheimer disease already developed and also it is not known how long the dementia patients should take the required drugs and how long the efficacy of administered drugs will remain effective. Therefore, there is a very urgent need to develop a therapeutic agent to treat dementia having excellent efficacies with little adverse effects.
Pulsatillae Radix is a perennial plant belonging to buttercup (Ranunculaceae) family of dicotyledon and has a few other names. The dried radix of Pulsatilla chinensis (Bge) Reg, P. koreana Nakai, P. cernua Var, P. patens and its species are used to prepare therapeutic agents having effects of defervescence, convergence, anti-inflammation, sterilization, etc., as well as an antidiarrheal resulted from dysentery. In Korean traditional folk medicinal therapies, it has been also used to treat malaria and neuralgia but there has been no scientific report that it has a therapeutic effect for treating dementia.